NSW Police have launched a strike force into alleged match-fixing in the NRL, a bombshell for the league on the eve of the finals series.

Dozens of players, officials and members of the community are expected to be interviews in coming months, with police warning the investigation is expected to be "protracted".

The news comes after NSW Police revealed in June that they were examining information relating to alleged fixing, before determining whether to take the matters further.

"The NSW Police Force has launched an investigation following a review of information into reported cheating at gambling and match-fixing in the National Rugby League," a police media statement read on Wednesday.

"Detectives from the state crime command's organised crime squad have launched strike force Nuralda to investigate the matters and determine if any criminal offences have been committed."

The NRL has confirmed they will support the investigation, providing any required assistance.

"We are not going to pre-judge any person associated with the game while this process is underway," NRL CEO Todd Greenberg said.

"But I repeat my earlier warning that if any person is convicted of match fixing they will face a life ban from any involvement in rugby league."

Reports in June linked two Manly games, one against South Sydney and the other Parramatta, to investigations.

A third Sea Eagles match, against Parramatta from this season, was later reportedly linked.